Optical assembly with encapsulated multilayer optical film and methods of making same

Patent metadata

Field	Value
Publication number	US-12214564-B2
Application number	US-202017780560-A
Country	US
Kind code	B2
Filing date	Dec 1, 2020
Priority date	Dec 6, 2019
Publication date	Feb 4, 2025
Grant date	Feb 4, 2025

Abstract

An optical assembly (200) including an encapsulated multilayer optical film (250). Methods of making and using such optical assemblies also are disclosed.

First claim

What is claimed is:

1. A method of making a shaped optical assembly including an encapsulated multilayer optical film, the method comprising:
i) forming an optical assembly blank by:
a) providing a female thermoforming mold having an internal mold cavity defined by a curved concave platen and a curved convex platen opposite the curved concave platen, wherein the curved convex platen and the curved concave platen are separable when the female thermoforming mold is open, separated by a first gap when the internal mold cavity is being injected with a molten resin, and separated by a second gap smaller than the first gap when the female thermoforming mold is closed;
b) opening the female thermoforming mold and positioning a multilayer optical film preform in contact with the curved convex platen, wherein the multilayer optical film preform has a curvature identical to that of the curved convex platen;
c) positioning a first hard coat film preform with a hard-coat in contact with the curved concave platen, wherein the first hard coat film preform has a curvature identical to that of the curved concave platen, the first hard coat film preform comprising a first (co) polymeric substrate having two opposed major surfaces and an at least partially cured hard coat layer on at least one of the opposed major surfaces, the at least partially cured hard coat layer being formed by at least partially curing a curable hard coat composition comprising:
A. 70 to 96 weight percent of at least one urethane (meth)acrylate compound having an average (meth)acrylate functionality of 2 to 9.58, based on the total weight of components A to D,
B. 2 to 20 weight percent of at least one (meth)acrylate monomer having a (meth)acrylate functionality of 1 to 2, based on the total weight of components A to D, optionally wherein the (meth)acrylate monomer does not comprise a urethane (meth)acrylate compound or a silicone (meth)acrylate,
C. an optional 0.5 to 2 weight percent of at least one silicone (meth)acrylate based on the total weight of components A to D,
D. an optional effective amount of at least one photoinitiator,
E. an optional plurality of inorganic nanoparticles and
F. optionally, at least one solvent;

d) injecting a first flowable material into the internal mold cavity while the curved concave platen and the curved convex platen are maintained separated by the first gap;
e) closing the female thermoforming mold to achieve the second gap and cooling the mold while maintaining the second gap in order to solidify the first flowable material and form the optical assembly blank;

ii) opening the female thermoforming mold and positioning the optical assembly blank in contact with the curved concave platen;
iii) positioning a second hard coat film preform in contact with the curved convex platen, wherein the second hard coat film preform has a curvature identical to that of the curved convex platen, the second hard coat film preform comprising a second (co) polymeric substrate having two opposed major surfaces and an at least partially cured hard coat layer on at least one of the opposed major surfaces, the at least partially cured hard coat layer being formed by at least partially curing a curable hard coat composition identical to the curable hard-coat composition of step (c);
iv) injecting a second flowable material into the internal mold cavity while the curved concave platen and the curved convex platen are maintained separated by the first gap;
v) partially closing the female thermoforming mold to achieve a third gap positioned between the first gap and the second gap and cooling the mold while maintaining the third gap in order to solidify the second flowable material and obtain the shaped optical assembly, wherein the multilayer optical film is encapsulated by the first and second flowable materials.

2. The method of claim 1 , wherein the shaped optical assembly has a maximum thickness of 3 mm or less, optionally wherein the shaped optical assembly has a radius of curvature of 65 to 68 millimeters.

3. The method of claim 1 , wherein the at least one urethane (meth)acrylate compound of component A includes at least one of an isocyanurate ring or a biuret group.

4. The method of claim 1 , wherein the at least one (meth)acrylate monomer of component B comprises at least one of 1,6-hexanediol di(meth)acrylate or an alkoxylated tetrahydrofurfuryl (meth)acrylate.

5. The method of claim 1 , wherein the at least one silicone (meth)acrylate of component C is present in the curable composition.

6. The method of claim 1 , wherein the effective amount of a photoinitiator of component D is present in the curable composition.

7. The method of claim 1 , wherein the plurality of inorganic nanoparticles of component E is present in the curable composition, optionally wherein the plurality of inorganic nanoparticles comprise α-alumina nanoparticles.

8. The method of claim 1 , wherein the at least one solvent of component F is present in the curable composition.

9. The method of claim 1 , wherein one or more of the first (co) polymeric substrate, the second (co) polymeric substrate, the first flowable material, and the second flowable material comprise one or more polycarbonate resins, optionally wherein at least one of following conditions applies: (i) the first flowable material is the same composition as the second flowable material; (ii) the first (co) polymeric substrate is the same composition as the second (co) polymeric substrate.

10. The method of claim 1 , wherein the first gap is from 1.51 to 2.5 mm, the second gap is from 1 to 1.5 mm, and the third gap is from 1.6 to 3 mm.

11. The method of claim 1 , wherein the multilayer optical film is a reflective polarizer film.

12. The method of claim 11 , wherein the reflective polarizer film comprises an optical stack, and wherein a major surface of the reflective polarizer film comprises a layer that is coextruded with the optical stack.

Assignees

• 3M Innovative Properties Company

Inventors

• Ambur Gregg A
• Dunn Douglas S
• Kostalik Iv Henry A
• Degraw Christopher S
• Klun Thomas P
• Coonce Benjamin R
• Pokorny Richard J
• Zhang Chunjie
• Froissard Laurent
• Warner Joseph S

Classifications

• G02B5/305

  including organic materials, e.g. polymeric layers · CPC title

• B29K2509/02

  Ceramics · CPC title

• B29K2105/162

  Nanoparticles · CPC title

• B29K2105/0002

  monomers or prepolymers · CPC title

• B29K2083/00

  Use of polymers having silicon, with or without sulfur, nitrogen, oxygen, or carbon only, in the main chain, as moulding material · CPC title